One step photographic transfer process



July 28, 1953 E. H. LAND ONE STEP PHOTOGRAPHIC TRANSFER PROCESS 2 Sheets-Sheet 1 Filed Feb. 12, 1948 Phorosensiiive Sheei Mqrerial Mafericll Processing Ageni FlG.

Layer of Processing Agenr Coniqiner for Processing Ageni INVE OR July 28, 1953 E. H. LAND ONE STEP PHOTOGRAPHIC TRANSFER PROCESS Filed Febi 12, 1948 2 Sheets-Sheet 2 Bdry'ta paper FIG. 6

Supper? Phoio. Emulsion I01: 3 Processing Agen'l' '0 IO b Silver PrecipH'qflng S+raum FIG. 7

Patented July 28, 1953;

ONE STEP PHOTOGBAPHIC TRANSFER OCE Edwin H. Land, Cambridge, Mass., assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware Application February 12, 1948, Serial No. 7,7 95

17 Claims.

This invention relates to photography, and more particularly to improved methods for treating a photosensitive material with a liquid processing agent.

This application is a continuation-in-part of application Serial No. 576,254, filed February 5, 1945, for Photographic Process, Apparatus and Product, now abandoned.

One object of the present invention is to provide a novel method for treating a predetermined area of a photosensitive material with a liquid processing agent, which method is characterized by the fact that no liquid baths are necessary and such equipment as distributes the processing agent throughout the area to be treated is not wetted by the liquid, the method being thus particularly adapted for use in a camera or other photographic apparatus to predeterminedly process a given area of a photosensitive material shortly after photo-exposure of said area in said apparatus.

Another object is the provision of a novel method of the foregoing type for processing a photosensitive material comprising as its photosensitive layer a silver halide emulsion or the like containing a latent image to cause the formation of a visible positive image of the subject matter of said latent image.

According to the process of the present invention, a processing agent is spread in a thin layer between a photosensitive material and another sheet material throughout an area at least coextensive with the area of the photosensitive material to be processed. The processing agent contains all the liquid required for the processing, and also contains a film-forming material which imparts thereto a predetermined high viscosity. The inclusion of the film-forming material serves several functions. In addition to increasing the viscosity of the agent to permit more uniform and controlled spreading thereof, the film-forming material provides for a more rapid and uniform wetting of the photosensitive material by the liquid of the agent. It serves to bond together at least temporarily the two sheet materials tightly enough to prevent separation or relative movement thereof during processing.

In a preferred form of the process, the processing agent is located between the photosensitive sheet material and the other sheet material adjacent to the area to be processed thereby in suflicient bulk to carry out the desired processing, and is thereafter spread in a thin layer throughout the area to be processed by progressively squeezing together successive increment areas of said sheet materials in the direction of the area to be processed. This makes possible a relatively close control of the thickness of the layer of processing agent and also of the area through which the processing agent is spread, and in turn makes unnecessary the excess of liquid which would be required if the distribution were nonuniform or uncontrollable as to the area of spread. In addition, the spreading of a viscous liquid between two sheets of material in this manner makes possible the processing of the photosensitive emulsion without any contact taking place between the liquid and the mechanism which accomplishes the spreading.

Moreover, by spreading the photographic reagent between two sheet materials, a lamination is formed whose outer layers prevent the penetration to any substantial extent of oxygen from the atmosphere to the intermediate. thin layer of liquid processing agent, thereby maintaining at a minimum the oxidation of the materials of the processing agent and making it possible to render the reagents in the processing agent inert to oxygen during the period of processing so that upon separation of the two sheets no further oxidation takes place.

It is possible by means of the process of the invention to carry out such photographic processes as require the predetermined permeation of a photosensitive material with a liquid processing agent. The processing agent spread between the photosensitive material and another sheet material contains all the liquid for carrying out the processing, but such photographic reagents as may be desired in the liquid to treat the photosensitive layer may either be dissolved or otherwise contained in the processing agent prior to the spreading thereof, or these reagents may be in part or wholly added to the agent as it is spread between the sheet materials, being so located on or adjacent the surface of one or both of said sheet materials as to be dissolved by or otherwise interacted with the liquid agent when the latter wets said surfaces.

Various photosensitive materials may be processed in accordance with the present invention. For example, a diazo print may be developed with a processing agent containing an alkali, or a ferric salt print may be developed with a processing agent which is an acidic aqueous solution, or a leuco dye base print may be treated by a processing agent which is arr alkaline aqueous solution. Similarly, a photosensitive silver halide emulsion or the like may be developed, or it may be developed and at least partially fixed, or a silver image in the photosensitive layer may be subjected to a predetermined toning or bleaching.

The process of the invention is, however, particularly advantageous for so processing a photosensitive silver halide emulsion layer or the like containing a latent image as to form a visible image of the subject matter of said latent image, which image is preferably a positive of said subject matter. In the performance of this preferred form of the process, the processing agent, when spread in a layer, is capable of developing a latent image in the area of the photosensitive layer over which it is spread and the development of this latent image produces an imagewise distribution, throughout the photosensitive layer and/or the liquid processing layer adjacent thereto, of a material which thereafter acts to provide the positive image in a layer other than the photosensitive layer.

In one form of this process, there is provided in the spread liquid composition a developing agent for the latent image and a material capable of forming a soluble complex with the photosensitive material of the emulsion. The complex-forming material and the developing agent react with the photosensitive layer in such a manner that the latent image is developed and a soluble complex is formed with the relatively unexposed, undeveloped photosensitive material of the emulsion. This complex is transported from the photosensitive layer and the silver thereof is caused to precipitate and aggregate in another layer of the lamination to form a positive image. As the liquid content of the intermediate layer of the liquid processing agent is absorbed by the two sheets between which it is spread and is in part evaporated through said sheets, the intermediate layer tends to solidify and to provide a coating of the film-forming material between the sheet materials. The silver of the soluble complex,may be caused to precipitate in this intermediate coating, or partly in said film and partly in a surface stratum of the other sheet material, or almost entirely in a surface layer of the other sheet material.

In other processes which may be carried out in accordance with the invention, the imagewise distribution of the developer or of the oxidation product of the developer, resulting from the development of a latent image in the photosensitive layer, is used to create said visible image in another layer of the lamination. In one such process, the imagewise distribution of the unused developing agent acts to form a substance which produces the visible image. In another modification, the oxidized developer is employed to react with a substance in a surface stratum of the other sheet material to form, for example, a dye image. This dye image is a negative of the subject matter of the latent image in the event the photosensitive emulsion is the ordinary nonsolarized emulsion, and is a positive of the subject matter of the latent image in the event the emulsion is of the type which gives direct positives upon exposure and development, e. g., emulsions which have been optically or chemically solarized or which use other reversal effects such as the Herschel effect.

In general, therefore, the process of the invention is particularly adapted for performing transfer processes wherein the layer of liquid composition which is located between the sheet material comprising the photosensitive layer and another sheet material acts to develop a latent image in said photosensitive layer, and, such development produces an imagewise distribution of a material which is capable of providing said other sheet material or the solidified film-forming material of the liquid layer with a visible positive or negative image record of the latent image. The inclusion of the film-forming material in the liquid composition in connection with these transfer processes serves further functions. It provides a spacer for the two sheet materials which tends to hold the same far enough apart so that there is a reservoir therebetween for the ions and molecules that must enter and leave the sheet materials during the processing while keeping the surfaces of said sheet materials near enough together so that the image-forming particles which are translated from the photosensitive layer are made up of components which have arrived along a relatively short radius of diffusion. The presence of the film-forming material in the liquid processing agent also serves to cause the latter to temporarily bond together the two sheet materials tightly enough to prevent such separation or relative movement thereof as might tend to diffuse the image being formed by the transfer process.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the process involving the several steps and the relation and the order of one or more of such steps with respect to each of the others which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

Figure 1 is an enlarged, fragmentary, and diagrammatic view in perspective illustrating one stage in carrying out the process of the present invention;

Fig. 2 is a view similar to Fig. 1 illustrating another step in the process of the present invention;

Fig. 3 is a view similar to Fig. 1 in which there is illustrated an alternative method for introducing the liquid processing agent between the two sheet materials;

Fig. 4 is a fragmentary, enlarged, perspective View illustrating the construction of the container which may be used in the process of the invention to provide the processing agent in a condition for spreading in a thin layer, the thicknesses of the laminations of the sheet materials from which the container is formed being greatly exaggerated;

Fig. 5 is a perspective View of the filled and sealed container;

Fig. 6 is a diagrammatic, enlarged, sectional view illustrating one embodiment of the process in operation; and

Fig. 7 is a view similar to Fig. 6 of another embodiment of the process in operation.

Referring to the drawings, and particularly to Figs. 1 and 2, there is illustrated one manner of performing the process of the present invention. A photosensitive sheet material In of which a predetermined area I2 is to be processed has a portion thereof, in advance of said area. located between a pair of pressure-applying members such as a pair of pressure rollers I4-l4 and another sheet material [6 is introduced between said pressure-applying members so that a portion thereof is superposed with respect to the portion of said photosensitive material located between said members. There is introduced into the troughlike cavity formed adjacent the pres sure-applying members by sheet materials H1 and 16 a mass 18 of the viscous film-forming processing agent in a quantity at least sufiicient to carry out the processing of said area, said mass of processing agent being preferably distributed throughout a length parallel to and coextensive with the linear dimension of said area which it adjoins. Thereafter, the sheet materials are moved in superposed relation between said pressure rollers so that the latter progressively apply a compressive force to successive increment areas of said sheet materials, spreading said processing agent i8 in a thin layer 29', as shown in Fig. 2.

The separation of the pressure rollers and the thickness of the sheet materials predetermine the maximum thickness of the layer of the liquid processing agent that is obtained between said sheet materials. Saidsheet materials may be moved with respect to said pressure rollers by being pulled therethrough manually, or by rotating the rollers to cause the frictional engagement between said rollers and said sheet materials to advance the latter therebetween, or by fixing the edges of said sheet materials extending through said rollers with a suitable clamp and thenmoving the rollers with respect to the sheet materials.

Other types of pressure-applying members such, for example, as a pair of nonrotatable bars or a pair of plates or a pair of jaw-shaped members or a plate and a roller may be employed instead of the pressure rollers to effect the spreading.

The processing agent may be dispensed between the sheet materials from a suitable container as, for example, a tubular, collapsible, metallic container of the type used for containing tooth paste, shaving cream, and the like. It will be observed (Fig. 1) that the liquid is located, upon dispensation, in a fairly concentrated mass i8 having a relatively small exposed surface area and that the relatively thin layer 20 of large surface area which is thereafter obtained by the spreading of the agent (Fig. 2) is protected on both sides thereof by the two sheet materials between which it is spread, thus minimizing the effects of oxidation.

The liquid composition may also be. provided in a condition to be dispensed and spread between said sheet materials H3 and I6 by being contained in an elongated container 22 which has a length at least equal to a transverse linear dimension of the area !2 of photosensitive material 10 to be processed. Container 22 is located between the two sheet materials adjacent and substantially parallel to an edge of said area which parallels said linear dimension.

Container 22, which may be attached to one of sheet materials It] and i6, is preferably inexpensive and disposable and so constructed as to be capable of retaining the processing composition therein for relatively long periods of time without vapor loss or oxidation. One example of a suitable container of this type is formed from a single multilayer sheet of material 30 (Fig. 4) comprising three layers, 3Ua, 35b and 300. Layer 36a, which provides the internal surface layer of the container, is formed of a material which is chemically inert to the processing agent and which is impervious to the liquid of the agent. One class of materials suitable for this purpose, particularly where the. processing agent is an alkaline solutionof a developer for silver halide or the like, is the polyvinyl acetals, and of the:

nitrocellulose, and approximately 5% by weight of dibutyl sebacate is particularly satisfactory as inner coating 39c. Layer Sikh-contiguous to layer 30a is preferably impervious to the vapor of the processing agent andis formed, for example, of

ametallic foil such as lead or silver foil. Backing layer 300, for example ofkraft paper, is provided and makes possible the use of thinner layers 30a and 30b.

The container 22 (Fig. 5) is preferably formed by taking the single sheet of material 38 and folding the same medially, as shown in Fig. 4, and thereafter securing the. end marginal portions 32 and the longitudinal portions 34 of thetwo folded faces to one another, providing a central space or cavity for containing the processing agent. To fill the container, it is possible to adhere together the opposite longitudinally extending marginal portions 34 and the end'marginal portions 32 at one end only of the container, the container being filled through the'other end, which is thereafter sealed.

The longitudinal seal between marginal portions 34 is preferably such that upon application of a predetermined compressive force to the walls of the container'there may be created within the container a sufiicient hydraulic pressure: to separate the marginal portions 34 throughout substanti'ally'their entire length. To insure this, the bond securing together said marginal portions 34 is somewhat weaker than the bond which secures together end marginal portions 32. For example, the end portions may be secured by pressing the two polyvinyl butyral inner surfaces together and applying heat thereto while a sealing strip 36 may be provided between the longitudinal marginal portions, which sealing strip is adapted to adhere to the inner layers ofpolyvin-yl butyral with a lesser afiinity than said layers adhere to one another in a direct polyvinyl butyral to polyvinyl butyral bond. Strip 36 may be formed of av material such as ethyl cellulose or a mixture of ethylcellulose and parafiin.

For carrying out the process of the invention wherein there is formed a positive image of the subject matter of a latent image contained in a photosensitive silver halide emulsion or the like, av preferred form of the processing agent comprises a water solution of a developer, an alkali for imparting tothe solution a sufiiciently high alkalinity to permit the developer to carry out its developing function, a substance for forming a soluble complex with silver halide, and a filmforming material. When this agent is spread between a photosensitive silver halide emulsion and another sheet material, the developer in the agent acts to develop any latent image in the emulsion and the silver halide solvent forms a soluble complex with the relatively unexposed silver halide during the development, which complex may be transported from the emulsion to another stratum of material of the lamination to form in said other stratum a, positive image comprising silver of the developed image in the emulsion. The film-forming material, which is preferably a high molecular weight polymer, imparts to the composition a predetermined high. viscosity and is: of such character as to retain its viscosity-imparting and film-forming properties in an aqueous alkaline solution so that the processing agent, once its ingredients have been mixed and have attained an equilibrium, remains uniformly viscous for any given temperature for long periods of time.

The film-forming material in the foregoing alkaline composition is preferably one of the class of high molecular weight polymers which include in their chemical structure such groups as, for example, the ether, alkyl, hydroxyl, carboxyl and acetyl groups that are stable to alkalies and which contain none of the chemical groups, such as the ester and acid chloride groups, that are unstable to alkalies. The polymers also contain groups such as the hydroxyl and/or carboxyl groups which tend to solubilize in aqueous alkaline solutions. Suitable examples of such polymers are the alkali-inert and water-soluble cellulose derivatives such as sodium carboxymethyl cellulose and hydroxyethyl cellulose, and the alkali-inert and water-soluble polyalkane derivatives such as polyvinyl alcohol and the sodium salts of polymethacrylic acid and polyaorylic acid.

A high viscosity for the processing agent is very desirable since it makes possible the relatively uniform spreading of the composition and insures a complete coverage of the desired area by said composition. The film-forming material is preferably contained in the composition in suitable quantities to impart to the composition a viscosity in excess of 1,000 centipoises at a temperature of approximately 24 C. and preferably of the order of 1,000 to 200,000 centipoises at said temperature. These high viscosities are important for any commercial application of said composition in view of the order of nonuniformity of commercially available materials and pressure-applying means to be used in connection therewith.

Examples of developers useful in the foregoing composition alone or in mixture with one another are hydroquinone, monomethyl-p-aminophenol sulfate (Elon, Metol), p-aminophenol hydrochloride (Kodelon), p-hydroxyphenylaminoacetic acid (Athenon, Glycin), p-phenylenediamine, o-phenylenediamine, pyrocatechin (pyrocatechol, catechol), diaminophenol dihydrochloride (Amidol), diaminophenol hydrochloride (Acrol), pyrogallol, chlorohydroquinone, dichlorohydroquinone, tetrachlorohydroquinone, bromohydroquinone, toluhydroquinone, xylohydroquinone, o-aminophenol, Z-amino-S-diethylaminotoluene hydrochloride, p-tertiary butyl catechol, hydroquinone disulfonic acid (potassium salt), 2,5-ditertiary butyl hydroquinone, and p-aminodiethylanaline.

Examples of materials which may be used in the composition for the purpose of forming a soluble silver complex with the undeveloped silver halide of the photosensitive layer are sodium thiosulfate, sodium thiocyanate, ammonium thiosulfate, ammonia and sodium cyanide. When a compound is toxic, such as sodium cyanide, precautions should be taken in the use thereof.

The composition may also contain sodium sulfite which acts in part as a preservative, and may also function as a silver halide solvent.

Examples of processes for forming a positive image of a. latent image contained in a silver halide emulsion by means of the transformation of undeveloped silver halide to a soluble complex and the translation thereof to a suitable imagereceiving layer are given below, but it is to be expressly understood that these examples are A processing agent is prepared which comprises:

Grams Water 1860 Sodium carboxymethyl cellulose 117 Sodium sulfite '78 Sodium hydroxide 74.6

Sodium thiosulfate 14.5 Citric acid 38.5 Hydroquinone 52 The processing agent is prepared by dissolving the sodium carboxymethyl cellulose, for example the commercially available Hercules 1362 medium viscosity type, in the water in a mixer at room temperature, and the solution is mixed therein for approximately one hour. Thereafter, the sodium sulfite, sodium hydroxide, sodium thiosulfate and citric acid are added to the solution, the addition being effected in an inert atmosphere, for example of nitrogen. Upon dissolution of these materials, the hydroquinone is added and the solution is further mixed for an hour at approximately room temperature in a nonoxidizing atmosphere of nitrogen.

The processing agent is then spread, for example as shown in Figs. 1 and 2, between a photosensitive sheet material l0 and another sheet material IE to form a laminate comprising sheet ID, a layer 20 of the processing agent, and sheet I6 (Fig. 6). Sheet [0 may comprise a support Illa of paper or transparent film base such as a cellulosic ester or a cellulose mixed ester and a photosensitive silver halide emulsion [012 such as an orthochromatic, high contrast emulsion especially useful for process work, for example, the emulsion of Eastman Kodak Contrast Process Ortho film, or an emulsion of an enlarging paper such as the emulsion of Eastman Kodak Kodabromide paper. This emulsion constitutes the inner surface of sheet In, and sheet material [8 is a baryta paper with the baryta coated surface thereof constituting its inner surface. The layer of processing agent 20 is preferably spread between said sheet materials to a thickness of between .002 inch and .003 inch. The absorption of the liquid by emulsion 10b and the surface portion of sheet material I6 promptly reduces this layer to a thickness of the order of .0001 inch to .0003 inch. Layer 20 bonds together sheet materials I0 and Hi just tightly enough so that they do not separate spontaneously during the time of processing. The lamination thus formed is kept intact for approximately one to two minutes, and at the end of this time sheet I6 is stripped from sheet I 0, leaving a finished positive image on sheet 16. The carboxymethyl cellulose is present in a continuous solid phase on the surface of the baryta paper and an appreciable amount of the silver which forms the positive image is precipitated in this carboxymethyl cellulose so that the image is at least partly formed therein. There is no appreciable wetting of the outer surfaces of sheet material In or [6 during the processing, the liquid being present in sufficiently small quantities to be substantially completely absorbed by the sheets.

Example 2 The processing agent of Example 1 may be modified by employing any one of the following developing agents in substantially the same quantity as the hydroquinone:

p-Aminophenol hydrochloride; bromohydroquinone; chlorohydroquinone; diaminophenol hydrochloride; diaminophenol dihydrochloride; toluhydroquinone; monomethyl-p-aminophenol sulfate; a mixture consisting by weight of onehalf hydroquinone and one-half p-hydroxyphenylaminoacetic acid; and a mixture consisting by weight of one-fourth hydroquinone and threefourths p-hydroxyphenylaminoacetic acid.

Example 3 The process of Example 1 may be carried out by employing the following processing agent in lieu of the processing agent described in Example 1:

Water cc 1000 Sodium sulfite g 70 Hydroquinone g 33 Sodium thiosulfate g 14 An aqueous solution of Hercules or Dow carboxymethyl cellulose, sodium salt, medium viscosity, consisting of 200 g. of

the latter compound in 1000 cc. of water cc 200 Sodium hydroxide, 10% solution cc 112 The foregoing materials may be mixed in the same Way as the materials of Example 1, or in the alternative, the sodium sulfite, hydroquinone, and sodium thiosulfate are dissolved in the water, and the sodium carboxymethyl cellulose solution is then added and thoroughly mixed therewith. The solution thus obtained is cooled to a temperature between 65 and 75 F. and thereafter the sodium hydroxide solution is added thereto.

Example 4 The process of Example 1 may be carried out by employing the following processing agent in lieu of the processing agent described in Example 1:

Water cc 1500 I-Iydroquinone g 28 Sodium sulfite g 200 Metol g 15.5 Sodium thiosulfate g 100 Aqueous solution of medium viscosity sodium carboxymethyl cellulose consisting of 200 g. of the latter compound in 1000 cc. of water g 1000 Sodium hydroxide g 56 Example 5 The process of Example 1 may be carried out by employing the following processing agent in lieu of the processing agent described in Example 1:

G. Sodium hydroxide 5 Sodium thiosulfate 1.5 Sodium sulfite 1 5.9

are dissolved in 65 cc. of water, and the solution is added to 190 g. of a solution of a high viscosity polyvinyl alcohol (du Pont PVA RH 391). There is added to the resulting mixture 5.2 g. of hydroquinone.

Example 6 The process of Example 1 may be carried out by employing the following processing agent in lieu of the processing agent described in Example 1:

500 grams of .hydroxyethyl cellulose, for example the product sold by Carbide and Carbon 10 Chemical Corp. and identified as Hydroxyethyl Cellulose (71.2 cps), is dissolved in 1000 cc. of water and 200 cc. of this solution is mixed with 500 cc. of a solution comprising the following.

G. Sodium sulfite 180 Sodium hydroxide 37.5 Hydroquinone 180 Sodium thiosulfate 50 Water to make 1500 Example 7 The process of Example 1 may be carried out by employing the following processing agent in lieu of the processing agent described in Example 1:

Sodium sulfite 78 Sodium hydroxide Sodium thiosulfate 15 Citric acid 39 Hydroquinone 52 are dissolved in 2860 cc. of distilled water, and there is added to this solution 102 g. of high molecular weight polymethacrylic acid. The resulting mixture is preferably treated in a vacuum pump to exclude oxygen and to remove the air content thereof, and comprises as its film-forming material the sodium salt of polymethacrylic acid, the polymethacrylic acid being neutralized in the alkaline solution.

If a relatively white and nontransparent film is to be formed by the liquid processing agent, there may be incorporated in any of the foregoing processing agents a suitable pigment such as titanium dioxide or mixtures of titanium dioxide and magnesium oxide or magnesium carbonate. The addition of titanium dioxide equivalent to from 10% to 20% by weight of the composition has given good results. These pigments also serve as fillers for increasing the viscosity of the composition.

Although sheet material [6 is preferably a baryta paper, it may be formed of such other materials as, for example, regenerated cellulose, a polyhydroxy alkane such as polyvinyl alcohol, sodium alginate, cellulose ethers such as ethyl cellulose, or their derivatives such as sodium carboxymethyl cellulose, aluminum carboxymethylcellulose and hydroxyethyl cellulose, other papers, proteins such as gelatin and carbohydrates such as gums and starch, and mixtures of these materials where the latter are compatible.

Faster emulsions such, for example, as the emulsions available for use in amateur photography as negative materials may also be used. Examples of the faster emulsions are the relatively high speed orthochromatic films, e. g., Eastman Kodak Verichrome film having an ASA speed rating of 0200 and an ASA exposure index rating in the daylight of 50, and the extremely high speed panchromatic emulsions, e. g., Eastman Kodak-Super XX Pan having an ASA speed rating of 04%00 and an ASA exposure index rating in. the daylight of 100, and Ansco Triple-S Pan. Preferably, When these higher speed emulsions are used, the sodium thiosulfate content of each of the preceding processing agents of Figs. 1 through 7 is substantially increased, being preferably quadrupled. Improvements in the photographic characteristics of the positive image may also be obtained by suitably treating the surface of sheet material It before the same is used in the process, for example, improved image color and contrast may be obtained by properly applying to the surface of the sheet material suitable substances for attracting and aggregating the image-forming ions. Examples of such substances are the metallic sulfides such, for example, as lead sulfide, cadmium sulfide, zinc sulfide, ferric sulfide, antimony sulfide, manganous sulfide, titanium sulfide, sodium sulfide, lanthanum sulfide, palladium sulfide, nickelous sulfide, and such metallic selenides as zinc selenide, nickel selenide, lead selenide, manganous selenide and antimony selenide, and such other substances as dithiooxamide and its lead and zinc complexes, potasium dithiooxalate and the lead complexes thereof, and thioacetamide.

For use with the foregoing faster films, these precipitating materials are preferably applied to the surface of the baryta in mixtures of a suitable, relatively inert material such as silica aerogel (Santocel C), wood flour, clays, for example kieselguhr and bentonite, starches, ground glass, and celites. Examples of suitable compositions for treating the baryta paper to form the sheet material It, which, when used in any of the foregoing transfer processes, particularly with the faster emulsions, will give a picture of improved quality, are the following:

baryta surface of the baryta paper, as by being rubbed thereon.

Example 9 1% solution of sodium sulfide cc 280 Silica aerogel (Santocel C) g 30 Solution containing 30 g. of cadmium acetate, 1 g. neutral lead acetate, and 30 g. of zinc nitrate dissolved in 100 cc. of

water cc 92 This mixture of materials is applied as a thin coating to the baryta surface of the baryta layer.

Example Baryta paper is run through a bath which is kept in contact with the baryta surface for approximately ten seconds, the bath comprising:

Cadmium acetate g 9 Neutral lead acetate g .3 Zinc nitrate g 18 Water cc 100 The sheet thus obtained is dried and coated with a mixture comprising:

Water cc 270 Cadmium acetate g 27.8 Lead acetate g 9.3 Zinc nitrate g 55.6 Silica aerogel (Santocel C) g 30 3% solution of sodium sulfide cc 94.7

The sheet is preferably dipped into this mixture and the excess mixture is removed from the sheet as, for example, by the action of a soft bufier roll on said sheet as it leaves the bath.

In each of the foregoing examples, the filmforming substance contained in layer 20 adheres which it contacts.

to sheet material It and strips away from emul sion Hlb when sheets l6 and ID are separated from one another, the positive image being formed in a stratum of the lamination comprising said sheet material It and the solid film obtained from said film-forming material. The process of the present invention may also be carried out by causing the film-forming material of layer 28 to adhere to photosensitive sheet material Hl instead of sheet material I6, so that the solid plastic film obtained from said film-forming material sticks to said photosensitive material Hl when the latter is stripped from sheet material I6.

By controlling the stratum in which the positive image is formed so that it is either on the surface or in the surface portion of sheet material l6, and then stripping from said sheet material the film obtained by the solidification of the film-forming material in layer 20, there is provided a positive print on sheet material I6 from which there has been stripped a substantial proportion of the substances which might otherwise in time deleteriously affect the positive print. In these processes, sheet material it comprises a base layer 16a (Fig. 7), for example of baryta paper, having one surface thereof suitably treated so that there is provided thereon or therein a precipitation stratum 16b. Over stratum IBb there is applied a layer I60, preferably very thin, of a material which has an appreciably lesser afiinity for the film-forming material of layer 20 than said film-forming material has for the surface of sheet material 10 In the event emulsion 10b is a silver halide gelatin emulsion and the filmforming material in layer 20 is sodium carboxymethyl cellulose, layer Hic may be, for example, gum arabic, cellulose a c e t a t e-lr y d r o g e n phthalate, polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, cellulose nitrate, sodium alginate, pectin, and polymethacrylic acid. Layer lfic preferably has a thickness of the order of 1 to 3 microns, although if it is relatively water permeable its thickness may be appreciably greater.

The adhesion between the carboxymethyl cellulose in layer 20 and the surface of layer lUb may also be increased by applying to said surface or by incorporating adjacent said surface in said emulsion a substance which tends to insolubilize sodium carboxymethyl cellulose by causing crosslinking of the molecules of the latter, examples of such substances being lead acetate and zinc acetate. The photosensitive emulsion may be treated with these materials by being dipped in a solution thereof. The afiinity between emulsion Iflb and the film-forming material of layer 20 may also be appreciably increased by applying to the surface of said emulsion a thin coating of solid film formed of said film-forming substance.

To provide a sheet [6 with a stratum lfib containing precipitation nuclei, a sheet of baryta paper may have the baryta surface thereof coated as described in Example 10, or it may be processed as follows:

Example 11 A sheet of baryta paper has roll coated thereon a thin layer of a composition comprising:

Cc. .25% solution of polyvinyl alcohol 1% solution of sodium sulfide 48 1% solution of neutral lead acetate 76 Either of the sheets processed in accordance with Examples 10 and 11 and thereby provided with an image-receiving stratum l6b may be suitably processed to b provided with a stripping overcoat I50, for example in the followin manner:

Example 12 The processed sheet has roll coated thereon against a smooth surface such, for example, as the polished surface of a metal drum, a aqueous solution of polyvinyl alcohol in a layer whose thiclmess is of the order of .001 inch. An equivalent amount by weight of hydroxyethyl cellulose or polymethacrylic acid may be substituted for the polyvinyl alcohol of this example.

Example 13 The processed sheet is dipped into a 2% solution of cellulose acetate, the cellulose acetate being dissolved in a mixture of methanol, ethyl acetate and methyl Cellosolve, the proportions of said solvents being in the ratio of 1 :3 :3 by volume, respectively. The dipped baryta paper is removed from the solution in a vertical position to permit the excess liquid to drip oil, a sufficient quantity of the solution remaining on the surface of the paper to provide the latter with a coatin of cellulose acetate of the desired thickness.

Example 14 A solution of cellulose acetate-hydrogen phthalate in acetone is roll coated on the processed sheet in a thickness of approximately .001 inch.

In a similar manner, such other materials as methyl cellulose, cellulose nitrate, sodium alginate, ethyl cellulose and gum arabic and pectin may be applied as layer I60 to the processed sheet. It is, of course, understood that suitable solvents for the materials are employed, said solvents being preferably water for such materials as are readily water soluble, and may be toluene for ethyl cellulose and a mixture of methanol and ethyl acetate for cellulose nitrate.

In using the sheets processed in accordance with any of the foregoing examples, the adhesion between the film-forming material and the photosensitive emulsion may be increased by applying to the photosensitive emulsion a thin coating of the film-forming material. For example, when the film-forming material in the processing agent is sodium carboxymethyl cellulose the surface of layer 0b may be treated as follows:

Example 15 A 5% water solution of sodium carboxymethyl cellulose is applied to layer lllb in a darkroom as, for example, by being spread thereon by a doctor blade to a thickness of approximately .002 inch. This film, when dried, will give a very thin layer of sodium carboxymethyl cellulose and will improve the adhesion between the layer [0b and the solid film formed from the processing agent.

It may be desirable in some instances to provide on the surfaces of sheet I6 2. single layer which combines the properties of layer I60 and stratum 1%, i. e., a single layer which serves to lessen the affinity between sheet material [6 and the film-forming material, and is so constituted as to attract the soluble silver halide complex and to precipitate the silver therefrom. Such a layer may be provided on base [6a, forexample as follows:

14 Example 16 A solution consisting of:

Water cc 270 Cadmium acetate g 27.8 Neutral lead acetate g 9.3 Zinc nitrate g 55.6

has mixed therewith a composition comprising:

Silica aerogel (Santocel C) g 30 1% solution of sodium sulfide cc 93.3

To cc. of the resulting mixture there is added 20 cc. of a solution of gum arabic such as Arabol. The mixture thus obtained is rubbed on a sheet as, for example, by a buffing roll in a thin layer onto a sheet of baryta paper which has been previously dipped for approximately ten seconds in a solution comprising:

Cadmium acetate g 9 Neutral lead acetate g .3 Zinc nitrate g 18 Water cc 100 Example 17 A sheet of baryta paper has roll coated thereon in a layer of a thickness approximating .002 inch a composition comprising:

8% solution of polyvinyl alcohol 220 4% solution of sodium sulfide 12 12% solution of neutral lead acetate 6 Example 18 A sheet of baryta paper has roll coated thereon in a layer of a thicknes approximating .002 inch a composition comprising:

Co. 50% solution of egg albumen 100 40% solution neutral lead acetate 48 1% solution sodium sulfide 15 15% solution ascorbic acid 9 Example 19 A sheet of baryta paper has roll coated thereon in a layer of a thickness approximating .002 inch a composition comprising:

Co. 50% solution of egg albumen 100 50% solution of gelatin 5 48% solution of neutral lead acetate 48 l solution sodium sulfide 15 15% solution ascorbic acid 9 As pointed out hereinabove, it is also within the purview of this invention to provide one or more of the ingredients which participates in the desired processing of the photosensitive layer in or on either of the faces of the two sheet material between which the composition is spread during the processing. These ingredients are preferably provided on said sheet materials in a condition such that they are rendered effective 'to perform their required function when dissolved in the liquid of the processing composition. For example, it is possible to provide the ions, e. g., thiosulfate, cyanide, or thiocyanate ions, which form the soluble silver complex with the unexposed silver halide in the foregoing process by providing a thiosulfate, cyanide, or thiocyanate salt on the image-receiving layer I6 which will dissolve in the processing liquid.

An example of this type of processing is, for example, the following:

Example 20 A sheet of baryta paper is dipped for sixty seconds in a bath which contains fifty grams of lead acetate and 100 cc. of water. This sheet is squeegeed and dried after the immersion and is then dipped for thirty seconds in another bath which contains 25 g. of sodium thiosulfate and 100 cc. of water. This second treatment causes the formation of lead thiosulfate in the surface of the baryta paper. The coating of lead thiosulfate may also be provided, for example, by adding to a 20% water solution of neutral lead acetate a 5% water solution of sodium thiosulfate and then rubbing the precipitate produced by this mixture onto the baryta paper. The baryta paper treated in either of these ways may then be employed as sheet IS in the process of the invention with its treated surface in contact with a layer 20 of processing agent comprising the following ingredients:

Water cc 1860 Sodium carboxymethyl cellulose g 93 Sodium sulfite g '78 Sodium hydroxide g 74.6 Citric acid g 38.5 Hydroquinone g 52 Sheet In may have as its emulsion layer 10b one of the faster emulsions such as the relatively high speed orthochromatic film or the extremely high speed panchromatic films. Examples of these emulsions are the Eastman Kodak Verichrome and Super XX Pan films. Layers l6 and Ill are held superposed for approximately one minute, at the end of which time the positive image is formed in the laminate comprising sheet [6 and the layer of film-forming composition formed by the liquid composition. The film strips readily from the gelatin of the photosensitive emulsion and adheres to the baryta paper when the latter is separated from the photosensitive material.

Example 21 A sheet material comprising a paper support Illa and a silver halide emulsion Ib, for example of the type used on Eastman Kodak Verichrome or on Super XX film, is dipped for one minute in a bath containing:

Hydroquinone g 2 Acetone cc 40 Water cc 60 The emulsion is then squeegeed to remove the excess liquid and then dried. To provide sheet material I 6, a sheet of single weight baryta paper is first coated with a thin layer of sodium carboxymethyl cellulose, for example by being run through a bath of a 5% solution of sodium carboxymethyl cellulose, the sheet being maintained in contact with the bath for approximately ten seconds. After being dried, the sheet is run through a second bath containing:

Nicotinic acid nitrate g 20 Lead nitrate g 40 Water cc 100 and is kept in contact with this bath for approximately ten seconds. To further process the sheet, a mixture is prepared by adding one part by volume of a solution consisting of:

Cadmium acetate g 60 Lead acetate g 2 Zinc nitrate g 60 Water cc 200 to three parts by volume of a solution consisting of: V

16 Sodium sulfide g 28 Silica aerogel g 300 Water cc 2800' To five parts by volume of the resulting mixture there i added one part by volume of a solution consisting of:

Silica aerogel g 30 1% solution of sodium sulfide cc 60 15% solution of ascorbic acid cc 36 40% solution of neutral lead acetate cc 192 To fifty parts by volume of this solution there is added one part by volume of a 5% water solution of polyvinyl alcohol. Into the resulting solution there is dipped the previously prepared baryta paper and upon removal of the sheet from the bath the excess liquid is removed by means of a soft rubber buffing roll, preferably rotating in a direction opposite to the direction of travel of said sheet. Between a sheet I6 prepared in the foregoing fashion and an emulsion IQ of the foregoing type there is spread a processing agent consisting of Water 1860 Sodium carboxymethyl cellulose 93 Sodium sulfite '78 Sodium hydroxide 74.6 Sodium thiosulfate 14.5 Citric acid l 38.5

The liquid is spread in the layer approximately .002 inch to .003 inch thick, and the developer in the emulsion is dissolved by the liquid content of the processing agent and caused to develop the latent image in the photosensitive emulsion and to participate in the reduction of the soluble silver halide complex to silver. Sheets i0 and I6 are kept assembled for approximately one minute, a finished positive image being formed on sheet l6 at the end of this time.

In the foregoing examples, such materials as nicotinic acid nitrate, lead nitrate, cadmium acetate, zinc nitrate, lead acetate, and ascorbic acid are applied to sheet Hi to provide an environment for the final image in which the developing agent is stable.

The process of the present invention also comprehends the spreading of a film-forming processing liquid between a photosensitive film and another layer of material to form as a result of the development of a latent image in said photosensitive layer a positive dye image of the subject matter of said latent image in another layer of the lamination. The following are examples of such processes:

Example 22 A viscous film-forming composition is prepared by mixing together the following materials:

5% water solution of sodium carboxymethyl cellulose g 60 Pyrocatechin g 2 Sodium hydroxide 1.5

g 2% water solution of Calcocid blue AX 200% (C. I. 715) cc 4 i7 lulose nitrate and polyvinyl alcohol, whose'thickness is of theorder of r0001 inch. To the coated surface-of this sheetthere is applied another-coating which is very thin, approximately 2000 1 inch to 10008 inch in thickness, of gelatin, the latter being cast, for example, from a 2% water solution thereof. These coatings provide the ce'l-iulose acetate butyrate with a surface to which a film of sodium carboxymethy'l cellulose win adhere. the liquid film-forming composition is spread in a relatively uniform thin layer between the emulsion side of the photosensitive sheet material and the coatedside of the other sheet material. l he developer in the liquid composition develops a latent image in the emulsion and-tans the gelatin in the developedareas. The-tanned' gelati-n takes up or has an affinity for the dye in the lidriid composition. This taking up of theii-ye "by the tanned portions of thegelatin produces a n imagewise concentration of the dye inthe layerof proc- -essing liquid. The two sheet materials t!) and 1T6 'are kept in their superposed relation for approximately five minutes and then are separated, the

plastic film formed bythe processing fluid adher- 'ing to sheet material 1 6. This layer of plastic film contains therein a positive dye image of the subject matter of the latent image in the photosensitive layer. The image is a bluish-green.

Example 23 As photosensitive sheet material It] there may be used a photosensitivepaper such asan extreme contrast material which yields positive ,photo copies from positive originals upon exposure to p-Nitrophenylacetonitrile g .2 Acetone cc -5 Water .cc =50 for about one minute, squeegeed, and treated to provide the baryta with a magenta coupler. Thereafter, sheet I 6 .andphotosensitive .sheeitinaterial ['0 have spread therebetweenaQlayerof .the

order of .002 inch to v.003 inch of a processing agent comprising:

2-amino-5-diethylamino-toluene hydrochloride g .4 Sodium carbonate 'g 10 5% solution of medium viscosity carboxymethyl cellulose g 60 Water 'cc 1'5 The-two .sheetmaterialsare keptin 'eontact for approximately twomin'utestand at the end of this ."time are separated. The autopos'itive paperhas a positive thereon of the subject matter to which it was exposed and there is obtained 'on thesur' face of the haryta paper a second positive magenta color of this subject matter.

In another form of the process of theipresent invention, a dye image is formed ma stratum of the sheet material I 6 and .the solid 'film obtained To carry out the process of the invention,

'18 from the film-forming "processing fluid 20 is lea-used to adhere to the photosensitive sheet material in rather than to said-sheet 16. The following is an example of such a process:

.Example 24 .A viscous film-processing composition is :provic'led'in'the same manner as in Example -22,.and photosensitive sheet material ID of the same type is employed. The other sheet material I6 is @formed by casting anex-tremely thin layer .of cellulose acetate on the baryta coated surface of a sheet of .baryta ,paper, the layer being preferably formedhybeingcast from a.2% solution of cellulose acetate in a mixture of methanol, ethyl ace telteand methylCellosolve, the proportions of the three solvents being-in the ratio of 173:3 by vol- *ume, respectively. The thin film is obtained by dipping the :baryta paper into this solution :and .then fremoving the same :in a vertical position to permit .the excess solution :to drip .toff, "a suflici'ent uantity of the solution remaining on the surface =ofithe1paper StOEgiVEPa film of desired thickness to providesaidibarytamaper with a coating of cellu- =loseacetate of ?the desired thickness. Thelli'qui'd sIJIEJCGSSlDgEt-gfit isspread-betweenthe coated side of .sheet material 46 and the emulsion side of photosensitive layer l 0 :and theadeveloper develops the latent image in the aphotosensitive .layer .and etan's the gelatin :in the neighborhood of the "developed portions thereof. The dye in the-liquid .pr'ocessi-ngagent is taken up by these tann'edrpor- .tions, producing an :imagewise disposition dye in the ;liquid composition. This :dye penetrates through :the co'ating -;of :cellulose acetate to provide a-stratum (of sheet material 1:6 with a positive :dye image. The separation 10f :sheet materials EI'O .and i6 causes the film-forming material of the liquid composition -;to :adhere to the surface :of :photosensitive sheet material I 0.

In the foregoing examples, .the process :of the present invention "has been illustrated ;in connection with .the formation of positive images in a stratum :of the lamination comprising sheet ma- -terials "1-0, I 6 and layer 20 other than the .photosensitive emulsion of said-layer. Llnzallthese proc- =esses therezalso takes place a predetermined treatment of the photosensitive aemulsion involving at least the development of the latent image therein. ltis tobe expressly understood also that the proc- -ess of the :present invention may :be performed solely :for the-purpose of subjecting .a photosensi- =tive emulsion to a predetermined processing-such, for example, as the development or toning of a ::latent or visible image therein. The :following rare examples .of this type of processing:

Example 25 A photosensitive sheet material 10 comprising as its photosensitive layer 10%; a layer containing a 'diazonium compound such, for example, as the photosensitive sheet materialsold "by 'theIBoston Blueprint Company as Blackline 202 may be used. The liquid composition, spread 'in a'layer 2.0 .between said photosensitive sheet .material and .a sheet material lfi for example of baryta .papenconsists -.of the following G. 5% solution of high viscosity sodium carboxymethyl cellulose =4 LBlac'kline developer 2032/ sold by the Boston Blueprint Company and manufactured by .Erede-rick Post (.70.,Chi0ago .8

Naphthosol Fast Blue Salt B. (C. I. 499) g Example 26 The process of Example 24 can also be carried out with a processing agent comprising:

Sodium carboxymethyl cellulose (high vis- Example 2? Either of the compositions of Examples 25 and 26 can also be used in connection with a diazonium photosensitive material formed by dipping a sheet of baryta paper in a bath consisting of Water 00.. 500 Pontacyl Green Blue (0. I. 666) g .2

By employing a film-forming material which is transparent and having sheet material 16 transparent, a transparency is obtained. By including a suitable pigment in the processing agent so that a white, opaque film is obtained when the layer of liquid is solidified, a positive print may be formed in layer 20 by the processes of any of Examples 1 through '7 in which the image is visible from the side of the solid film adjacent sheet material I0. When layer 20 contains a White pigment and there is provided on the surface of layer [B a precipitating stratum |6b in accordance with the process of Examples 10 and 11, a silver image is formed in said stratum 16b and is visible against the white, opaque film obtained by the solidification of layer 20. By using a sheet I6 which is transparent, it becomes unnecessary to strip sheet material [6 from sheet material I 0, the image being visible through said sheet material [6.

In the event that the processing agent is a nonalkaline solution, such other film-forming materials as starch, sodium alginate, and gelatin may be employed. Examples of suitable starches are Mercks starch, Argo starch, Maine potato starch, and Brazilian starch. In general, sodium alginate is used in approximately the same proportions as the sodium carboxymethyl cellulose of the foregoing examples, and starches are preferably used in a concentration approximately twice that of the sodium carboxymethyl cellulose.

Although water alone is the solvent for the viscous processing agent in many of the foregoing examples, other solvents may be used, for example acetone and methanol, in mixture with water.

The film-forming material in the processing agent solidifies as the liquid of the processing agent is absorbed or evaporated from the layer thereof, but the solidification is not necessarily complete at the time of separation of thetwo sheet materials after processing. The coating of the film-forming material after separation of the sheet materials may contain an appreciable quan-- tity of liquid which is thereafter removed either by evaporation or by being absorbed into the sheet material to which said coating adheres.

An important function of the viscous filmforming processing agent in the transfer processes is that it may allow small time lags'in relating portions of the negative-producing cycle to portions of the positive-producing cycle because of the separation which it maintains between the sheet materials. It also makes possible the postponement of action of ingredients located in one sheet upon the other sheet until the initiation of a desired reaction in said other'sheet.

Since certain changes may be made in the above process without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. The method of forming an image in a predetermined area of a photosensitive layer of a photographic, photosensitive sheet material, said photosensitive layer having as its photosensitive substance at least one compound from the class consisting of the photosensitive silver halides and diazonium compounds, which method comprises locating a viscous liquid processing agent adjacent one edge of said area at least in suflicient quantit to provide all the liquid required for a transformation of an image formed in said photosensitive layer by photoexposure, said processing agent being located on one side only of said photo-sensitive sheet material and containing a solid film-forming high molecular weight polymer in suflicient quantity to impart to said processing agent a viscosity in excess of 1000 centipoises at 24 C., forming a layer of said processing agent between said photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheet materials, the portions of said outer surfaces subjected to said pressure remaining dry during'said pressure application, liquid from said processing agent being absorbed by said photosensitive sheet material and, during absorption, distributing, throughout said area of said photosensitive layer, a photographic reagent capable of carrying out the desired image transformation, said photographic reagent being different from the solvent of said processing agent and being provided by one of (a) said sheet materials and (b) said processing agent, the absorption of said liquid from said layer of processing agent increasing the concentration of said polymer in said liquid to produce a coating containing said polymer between said sheet materials which maintains the latter in spaced laminated relationship during the processing.

2. The method of producing a visible record of a latent image contained in a predetermined area of a silver halide layer of a photosensitive sheet material, which method comprises locating a viscous liquid processing agent on one side onl of said photosensitive sheet material adjacent one edge of said area at least in sufiicient quantity to provide all the liquid for the development of said latent image, which processing agent contains an organic high mo-- lecular weight film-forming polymer, spreading said processing agent in a layer between said photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheet materials, the portions of said outer surfaces subjected to said pressure remaining dry during said pressure application, liquid from said processing agent being absorbed by said photosensitive sheet material and, during absorption, distributing, throughout said area of said photosensitive layer, photographic material, including a silver halide developer, capable of developing a latent image in said photosensitive layer and of producing an imagewise distribution throughout the liquid of a material for forming a transfer print of said latent image,

at least part of said photographic material being dissolved from one of said sheet materials, the absorption of said liquid from said layer of anew-056 processing agent producing a coating of said film-forming polymer between said sheet materials which maintains the latter in spaced, laminated relationship during the processing, re- Itaining said sheet materials in their superposed condition until there is transported from the photosensitive layer a quantity of said imageforming material sufiicient to form said visible record in a stratum of the laminationcomprising said coating and said other sheet material, :and stripping said lamination from said photosensitive sheet material.

3. The method of producing a visible positive image of the subject matter of a latent image contained in a predetermined area of a silver halide layer of a photosensitive sheet material, which method comprises locating a viscous liquid processing agent on one side only of said photosensitive sheet material adjacent one edge of said area at least in sufficient quantity to provide all the liquid for the development of said latent image, which processing agent contains a film-forming high molecular weight polymer, spreading said processing agent in a layer between said photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheet materials, the portions of said outer surfaces subjected to said pressure remaining dry during said pressure application, liquid from said processing agent being absorbed by said photosensitive sheet material and, during absorption, distributing, throughout said area of said photosensitive layer, photographic material including a developer for the silver halide and a silver halide solvent capable'of forming a solublesilver complex with the undeveloped silver halide, said photographic material being provided by at least one of (a) said sheet materials and (7)) said processing agent, the development of said latent image producing an imagewise distribution of said soluble silvercomplex throughout the liquid-of said processing agent, the absorption of said liquid from said layer of processing agent producing a coating of said film-forming polymer between said sheet materials which maintains the latter in spaced, laminated relationship during the processing, and retaining said sheet materials in their superposed condition until there is transported from the photosensitive layer a quantity of said soluble silver complex suificient to form said positive image in a stratum of the lamination comprising said coating and said other sheet material.

4. The method of producing a visible positive image or the subject matter of a latent image contained in a predetermined area of a silver halide layer of a photosensitive sheet material, which method comprises locating a viscous liquid processing agent on one side only of said photosensitive sheet material adjacent one edge of said area at least in sufficient quantity to provide all the liquid for the development of said latent image, which processing agent contains a film-forming high molecular weight polymer, spreading said processing agent in a layer between said photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheet materials, liquid from said processing agent "being absorbed by said photosensitive sheet material and, during absorption, distributing, throughout said area of said photosensitive layer, photographic material including a developer for the silver halide and a silver halide solvent capable of forming a soluble silver complex with the undeveloped silver -halide, said photographic material-being provided by at least one of (a) said sheet materials and (b) said processing agent, the development of said latent image producing an imagewise 'distribution of said soluble silver complex throughout the liquid of said processing agent, the "absorption of said liquid from said layer of processing agent producing a coating of said filmforming polymer between said sheet materials which maintains the latter in spaced, laminated relationship during the processing, retaining said sheet materials in their superposed condition 'until there is transported from the photosensitive layer a quantity of said soluble complex sufficient to form said positive image, at least a part of said complex being precipitated in said coating, and stripping said other sheet material, with the coating of film-forming polymer attached thereto, from said photosensitive :sheet material.

5. The method of producing a visible image of a latent image contained in a predetermined area of a silver halide layer of a photosensitive sheet material, which method comprises locating a viscous liquid processing agent on one side only of said photosensitive sheet :material adjacent one edge of said area at least in sufficient quantity to provide all the liquid for the development of said latent image, which processing agent contains a film-forming high molecular weight polymer, spreading said processing agent in a layer between said photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheet materials, liquid from said processing agent being absorbed by said photosensitive sheet material and, during absorption, distributing, throughout said area of said photosensitive layer, photographic material capable of developing a latent image in said photosensitive layer and of producing an imagewise distribution throughout the liquid of a material for forming a transfer print of said latent image, said photographic material being provided by at least one of (a) said sheet materials and (b) said processing agent, said other sheet material comprising an image-receiving stratum adjacent the surface thereof for said image-forming material, retainsheet material is transparent so that a transparency is obtained.

'7. The method of claim 5 wherein the other sheet material is opaque so that'a reflection print is obtained.

8. The method of producing a visible positive image of a latent image contained in a predetermined area of a silver halide layer of a'photosensitive sheet material, which method comprises locating a viscous liquid processing agent on one side only of said photosensitive sheet material adjacent one edge of said area at least in sufficient quantity to provide all the liquid for the development of said latent image, which processing agent contains an organic film-forming high molecular weight polymer, spreading said processing agent in a layer between said photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheet materials, the portions of said outer surfaces of said sheet materials subjected to said pressure remaining dry during said pressure application, the surface of said other sheet material in contact with said liquid layer having coated thereon a film having a lesser affinity for said film-forming polymer in its solid state than the solid organic film-forming polymer has for the surface of the photosensitive sheet material, liquid of said processing agent being absorbed by said photosensitive sheet material and, during absorption, transporting, to said area of said photosensitive layer, photographic material including a developing agent for the silver halide and a silver halide solvent capable of forming a soluble silver complex with the undeveloped silver halide, said photographic material being provided by at least one of (a) said sheet materials and (b) said processing agent, the development of said latent image producing an imagewise distribution of said soluble silver complex throughout the liquid of said processing agent, said other sheet material comprising an image-receiving stratum adjacent the surface thereof containing nuclei for aggregating and precipitating the silver of a soluble silver complex, retaining said sheet materials in their superposed condition until the absorption of said liquid from said layer of processing agent produces a continuous solid phase of said organic film-forming polymer between said sheet materials and there is transported from the photosensitive layer through said film-forming polymer a quantity of said soluble silver complex sufficient to form in said image-receiving stratum a visible positive image of the subject matter of said latent image, and stripping said photosensitive sheet material, with the layer of film-forming polymer attached thereto, from said other sheet material and the image formed therein.

9. The method of producing a visible positive image of a latent image contained in a predetermined area of a silver halide layer of a photosensitive sheet material, which method comprises locating a viscous or liquid processing agent on one side only of said photosensitive sheet material adjacent one edge of said area at least in sufficient quantity to provide all the liquid for the development of said latent image, which processing agent contains an organic film-forming high molecular weight polymer, spreading said processing agent in a layer between said photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheet materials, the portions of said outer surfaces of said sheet materials subjected to said pressure remaining dry during said pressure application, the surface of said photosensitive sheet material in contact with said liquid layer having coated thereon a solid film of said organic filmforming polymer and the surface of said other sheet material in contact with said liquid layer having coated thereon a solid film having a lesser aiflnity for said organic film-formin polymer in its solid state than said film-forming polymer has for the coated surface of the photosensitive sheet material, liquid of said processing agent being absorbed by said photosensitive sheet material and, during absorption, transporting, to said area of said photosensitive layer, photographic material including a developing agent for the silver halide and a silver halide solvent capable of forming a soluble silver complex with the undeveloped silver halide, said photographic material being provided by at least one of (a) said sheet materials and ('0) said processing agent, the development of said latent image producing an imagewise distribution of said soluble silver complex throughout the liquid of said processing agent, said other sheet material comprising an image-receiving stratum adjacent the surface thereof containing nuclei for aggregating and precipitating the silver of a soluble silver complex, retaining said sheet materials in their superposed condition until the absorption of said liquid from said layer of processing agent produces a continuous solid phase of said film-forming polymer between said sheet materials and there is transported from the photosensitive layer through said film-forming polymer a quantity of said soluble silver complex sufiicient to form in said image-receiving stratum a visible positive image of the subject matter of said latent image, and stripping said photosensitive sheet material with the layer of film-forming polymer attached thereto, from said other sheet material and the image formed therein.

10. The method of producing a visible image of a latent image contained in a predetermined area of a silver halide layer of a photosensitive sheet material, which method comprises locating a viscous liquid processing agent on one side only of said photosensitive sheet material adjacent one edge of said area at least in sufficient quantity to provide all the liquid for the development of said latent image, which processing agent contains an organic film-forming high molecular weight polymer, spreading said processing agent in a layer between said photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheet materials, the surface of said other sheet material in contact with said liquid layer having a lesser affinity for the solidified film-forming polymer than the latter has for the surface of the photosensitive sheet material, liquid from said processing agent being absorbed by said photosensitive sheet material and, during absorption, distributing, throughout said area of said photosensitive layer, photographic material capable of developing a latent image in said photosensitive layer and of producing an imagewise distribution throughout the liquid of a material for forming a transfer print of said latent image, said photographic material being provided by at least one of (a) said sheet materials and (b) said processing agent, said other sheet material comprising an image-receiving stratum adjacent the surface thereof for receiving said image-forming material, retaining said sheet materials in their superposed condition until the absorption of said liquid from said layer of processing agent at least partly solidifies said film-forming polymer and there is transported from the photosensitive layer through said filmforming polymer a quantity of said image-forming material sufficient to form in said image-receiving stratum a visible image of the subject matter of said latent image, and stripping said photosensitive sheet material, with the layer of film-forming polymer attached thereto, from said other sheet material.

11. The method of producing a visible positive image of a latent image contained in a predetermined area of a silver halide layer of a photosensitive sheet material, which method comprises locating a viscous liquid processing agent on one side only of said photosensitive sheet material ad- Jacent one edge of said area at least in suflicient quantity to provide all the liquid for the development of said latent image, which processing agent comprises ('1). a developer; for silver'halide; (2') a silver halide solvent for forming: a soluble. com.- plex with silver. halide: and: (3') sodium. carboxymethyl cellulose, spreading: saidprocessing agent in a layer between said photosensitive sheet material' and anothersheet material by? applying pressure to the outer surfaces. ofi said: sheet; materials',. the portions of said: outer surfaces sub.- jected to said pressure remaining dry during said pressure application, liquid of said. processing agentbeing absorbed by said photosensitive sheet material and, during absorption, transporting said developing agent" and saidsilver halide'solvent to said area of said photosensitive layer, and retaining said sheet materials. in their superposed condition until the absorption of. said liquid from said layer of processing agent produces a continuous solid phase of said sodium carboxymethyl cellulose between said sheet materials and there is transportedirom the phc tosensitive layer a quantity of said soluble silver complex suificient to form said visible positive image of the subject matter of said latent image in a stratum of the lamination comprising said two sheet materials and said layer" of processing agent, said stratum being other than said photosensitive layer.

12. The method of producing a visible positive image of a latent image contained in a predetermined area of asilver halide layer of a. photosensitive sheet material which method comprises locating a viscous liquid processing agent on one side only or" said photosensitive sheet material adjacent one edge of said area atleast in sufficient quantity to" provide all the liquid for the development of said latent image, which processing agent comprises (1) a developerfor silver halide, (2) a silver halide solvent for-forming a soluble complex with. silver halide and hydroxyethyl cellulose, spreading said processing agent in a layer between said. photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheetmaterials, the portions-oi said outer surfaces subjected to said pressure remainingdry during'said pressure application,, liquid. of. said processing agent being absorbed by said photosensitive sheet material. and, during absorption, transporting said developing agent and said silver halide solvent to said area of said photosensitive layer, and retaining said sheet materials in their superposed condition until the absorption of said liquid from said layer of processing agent produces a continuous solid phase of said hydroxyethyl cellulose between said sheet materials and there is transported from the photosensitive layer a quantity or said soluble silver complex suflicient to form 5;

said visible positive ima e of the subject matter of said latent image in a stratum of the lamination formed by said two heet materials and said layer of liquid processing agent, said stratum being other than said photosensitive layer.

13. The method of producing a visible positive image of a latent image contained in a predetermined area of a silver halide layer of a photosensitive sheet material, which method comprises locating a liquid processing agent on one side only of said photosensitive sheet material adjacent one edge of said area at least in sufiicient quantity to provide all the liquid for the development of said latent image, which processing agent is alkaline and comprises hydroquinone, sodium thiosulfate and sodium carboxymethyl cellulose in a sufficient concentration to impart to said processing agent a viscosity at 24 C. in excess of 1000 centipoises, spreading said processing agent in a layer between said photosensitive sheet materi'al and another sheet material by' applying pressure. to the outer surfaces of said: sheet: materials, the portions of said outer surfaces: of said sheet materials subjected to said pressure remaining dry during said: pressure application, liquid of said processing agentbeing' absorbed. by said photosensitive sheet material and, during absorption, transporting the hydroquinone' and the sodium thiosulfate to said. area of said photosensitive layer; and retaining said: sheet materials in their superposed condition until the absorption of said liquid from said layer of processing: agent produces a continuous: solid phase of said sodium carboxymethyl cellulose between said sheet. materials' and there is transported from the photosensitive: layer: a quantityof said soluble silver complex sufficient to form said visible positive image of the subject matter of said latent image in a stratum of the lamination. formed. by." said two sheet materials and: said layer of: liquid processing agent, said stratum being. other: than said photosensitive layer;

14. The method of. producing avisible positive image of. a latent image contained in a predeter mined.v area of a silver halide gelatin emulsion layer of a photosensitive film, which method com;- prises locating a liquid processing agent on one side only of. said film. adjacent one edge of: said area at least in sufiicient quantityto provide all the liquid for the development. of said latent image, said processing agent comprising. an alkaline aqueous solution of sodium carbonymethyl cellulose, hydroquinone and. sodium thio. sulfate and having. a viscosity. at 214 C3 excess of 1000 centipoises,. spreading said processing agent in, a layer between said film and a sheet of baryta paper by applying pressure to the outer surfaces of said film and; said paper;v the portions of said. outer surfaces: subjected: tosaid pressure remaining dry during. said pressure application, liquid of said processing agent being; absorbedby said emulsion and, during absorption, transport ing the hydroquinone: and the sodiumthiosulfat'e thereto, and retaining saidifil'm and said paperin their superposed condition until the absorption of said liquid from; said layer of. processing. agent produces a continuoussoli'dmhase-of. sodium carboxymethyl cellulose between. said film. and. said paper and there is transported from the photosensitive layer to the lamination comprising the calboxymethyl cellulose and the paper a quantity of said soluble silver complex sufficient to form in a stratum of said lamination said visible positive image of the subject matter of said latent image.

15. The method of producing a visible positive image of a latent image contained in a predetermined area of a silver halide layer of a photosensitive sheet material, which method comprises locating a viscous liquid processing agent on one side only of said photosensitive sheet material adjacent one edge of said area at least in sufficient "quantity to provide all the liquid for the development of said latent image, which processing agent contains a developer for silver halide, a silver halide solvent for forming a soluble complex with silver halide and a high molecular weight polymer in a sufiicient concentration to impart to said processing agent a viscosity at 24 C. in excess of 1000 centipoises, spreading said processing agent in a layer between said photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheet materials, the portions of said outer surfaces subjected to said pressure remaining dry during said pressure application, liquid of said processing agent being absorbed by said photosensitive sheet material and, during absorption, transporting said developing agent and said silver halide solvent to said area of said photosensitive layer, and retaining said sheet materials in their superposed condition until the absorption of said liquid from said layer of processing agent produces a coating of said high molecular weight polymer between said sheet materials and there is transported from the photosensitive layer a quantity of said soluble silver complex sufficient to form said positive image in a stratum of the lamination comprising said coating and said other sheet material.

16. The method of forming an image in a predetermined area of a photosensitive layer of a photographic photosensitive sheet material, said photosensitive layer having as its photosensitive substance at least one salt from the class consisting of (a) the photosensitive diazonium salts and (b) the heavy metal salts capable of forming a latent image upon photoexposure and capable of development to produce a visible image comprising the metal of said salt, which method comprises locating a viscous liquid processing agent adjacent one edge of said area in sufficient quantity to provide at least part of the liquid required for a transformation of an image formed in said photosensitive layer by photoexposure, said processing agent being located on one side only of said, photosensitive sheet material and containing a solid film-forming organic colloid, forming a layer of said processing agent between said photosensitive sheet material and another sheet material by applying pressure to the outer surfaces of said sheet materials, the portions of said outer surfaces subjected to said pressure remaining dry during said pressure application, liquid from said processing agent being absorbed by said photosensitive sheet material and, during absorption, distributing, throughout at least a portion of said area of said photosensitive layer, a photographic reagent capable of carrying out the desired image transformation, said photographic reagent being different from the solvent of said processing agent and being provided by at least one of (a) said sheet materials and (b) said processing agent, the absorption of said liquid from said layer of processing agent increasing the concentration of said colloid in said liquid to produce a coating containing said colloid between said sheet materials which maintains the latter in spaced laminated relationship during said processing.

17. The process of claim 16 wherein the photosensitive layer is a silver halide emulsion and the reagent is a substance from the class consisting of the silver halide developers and the silver halide solvents.

EDWIN H. LAND.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 312,451 Ehret Feb. 17, 1885 935,115 Kelly et al Sept. 28, 1909 1,170,506 Blondel Feb. 8, 1916 1,939,026 Spencer Dec. 12, 1933 2,029,922 Heckel et al Feb. 4, 1936 2,035,650 Gustafson Mar. 31, 1936 2,054,448 Russell Sept. 15, 1936 2,059,887 Mannes et a1. Nov. 3, 1936 2,072,597 Keen Mar. 2, 1937 2,113,944 Leuch Apr. 12, 1938 2,121,397 Downing June 21, 1938 2,196,226 Murray Apr. 9, 1940 2,273,677 Wallach Feb. 17, 1942 2,317,750 Fermazin Apr. 27, 1943 2,320,108 Tull May 25, 1943 2,323,246 Schneider June 29, 1943 2,328,034 Sease Aug. 31, 1943 2,350,380 White June 6, 1944 2,352,014 Rott June 20, 1944 2,386,602 Giosefli Oct. 9, 1945 2,417,713 Stein Mar. 8, 1947 FOREIGN PATENTS Number Country Date 9,248 Great Britain 1905 115,331 Switzerland June 16, 1926 141,872 Austria May 25, 1935 879,995 France Dec. 10, 1942 OTHER REFERENCES Colson Le Developpement Confine Bulletin societe Francaise Photographie 1898, pp. 108-111. 

1. THE METHOD OF FORMING AN IMAGE IN A PREDETERMINED AREA OF A PHOTOSENSITIVE LAYER OF A PHOTOGRAPHIC, PHOTOSENSITIVE SHEET MATERIAL, SAID PHOTOSENSITIVE LAYER HAVING AS ITS PHOTOSENSITIVE SUBSTANCE AT LEAST ONE COMPOUND FROM THE CLASS CONSISTING OF THE PHOTOSENSITIVE SILVER HALIDES AND DIAZONIUM COMPOUNDS, WHICH METHOD COMPRISES LOCATING A VISCOUS LIQUID PROCESSING AGENT ADJACENT ONE EDGE OF SAID AREA AT LEAST IN SUFFICIENT QUANTITY TO PROVIDE ALL THE LIQUID REQUIRED FOR A TRANSFORMATION OF AN IMAGE FORMED IN SAID PHOTOSENSITIVE LAYER BY PHOTOEXPOSURE, SAID PROCESSING AGENT BEING LOCATED ON ONE SIDE ONLY OF SAID PHOTO-SENSITIVE SHEET MATERIAL AND CONTAINING A SOLID FILM-FORMING HIGH MOLECULAR WEIGHT POLYMER IN SUFFICIENT QUANTITY TO IMPART TO SAID PROCESSING AGENT A VISCOSITY IN EXCESS OF 1000 CENTIPOISES AT 24* C., FORMING A LAYER OF SAID PROCESSING AGENT BETWEEN SAID PHOTOSENSITIVE SHEET MATERIAL AND ANOTHER SHEET MATERIAL BY APPLYING PRESSURE TO THE OUTER SURFACES OF SAID SHEET MATERIALS, THE PORTIONS OF SAID OUTER SURFACES SUBJECTED TO SAID PRESSURE REMAINING DRY DURING SAID PRESSURE APPLICATION, LIQUID FROM SAID PROCESSING AGENT BEING ABSORBED BY SAID PHOTOSENSITIVE SHEET MATERIAL AND, DURING ABSORPTION, DISTRIBUTING, THROUGHOUT SAID AREA OF SAID PHOTOSENSITIVE LAYER, A PHOTOGRAPHIC REAGENT CAPABLE OF CARRYING OUT THE DESIRED IMAGE TRANSFORMATION, SAID PHOTOGRAPHIC REAGENT BEING DIFFERENT FROM THE SOLVENT OF SAID PROCESSING AGENT AND BEING PROVIDED BY ONE OF (A) SAID SHEET MATERIALS AND (B) SAID PROCESSING AGENT, THE ABSORPTION OF SAID LIQUID FROM SAID LAYER OF PROCESSING AGENT INCREASING THE CONCENTRATION OF SAID POLYMER IN SAID LIQUID TO PRODUCE A COATING CONTAINING SAID POLYMER BETWEEN SAID SHEET MATERIALS WHICH MAINTAINS THE LATTER IN SPACED LAMINATED RELATIONSHIP DURING THE PROCESSING. 